Hi guys, the Sportsman II heads I just installed are the first heads I've ever dealt with that use adjustable guide plates, instead of just machined pushrod guide slots in the heads. I adjusted the guide plates so that the rollers on my roller tipped rockers were centered over the valve stem as well as I could center them. However, this puts several of the pushrods very close to the edge of the pushrod holes drilled through the heads. Yeah I should have ground them out w/ a die grinder when I had the intake off, but being in a hurry I assembled everything already. I can still use a high powered shop vac and a magnet on a stick to let me grind on the heads w the engine assembled, although I hate to do that.

How close is too close pushrod to head, on heads w/ adjustable guide plates? I'm thinking of running the engine w/ the valve covers off, and sliding a feeler gage in between the pushrod and head to see what the running clearance is. It appears to be about 10 thousandths clearance or less. The engine runs excellent with no valve train noise, but I have only started it to drive around the parking lot. I'm going to deal w/ the pushrod clearance before I really drive the car anywhere.

Thanks

Steve

 

The rockers aren't supposed to be centered over the valve stems. They're supposed to be off to the side a little bit (operative concept being "a little bit") to help rotate the valves.

In any case, they won't stay centered over the valve stems throughout their cycle; the rocker stud spacing, guide plate slot spacing, and the valve spacing are all different.

Their EXACT location is not critical.

Don't forget to put sealer on the bottom half of the rocker studs; the intake ones likely go RIGHT DIRECTLY INTO the intake ports and will therefore leak oil into the intake, and the exhaust ones usually go into water. I don't recall what the S2 heads do, but it's better to err on the safe side. I prefer either the Permatex "automotive pipe thread sealer with Teflon", or the brown gooey Permatex 300 that you put on with a brush.

 

When I "centered" the rockers, I viewed them as a pair, and made sure that the pair was centered over the two valves. This does not put each rocker tip directly over each valve tip, as you pointed out. However, with the pair of rockers centered over the pair of valves, I am having my pushrod clearance issue. I didn't put any sealant on the studs. Add that to the to do list!

 

How close is too close? TOUCHING is too close. Anything other than touching is fine.